1. Field of the Invention
The present invention relates in general to a method of fiber scouring. More particularly, it relates to a method for removing oil agents from fibers using supercritical carbon dioxide as an extraction media.
2. Description of the Related Arts
As known in the art, spinning oils and finishing oils are respectively applied to the surface of artificial fibers when they are subjected to spinning and false twisting. The most commonly used spinning oils are ethylene oxide/propylene oxide (EO/pO) copolymer ester, while finishing oils are commonly coning oils. The spinning and finishing oils must be scoured from the fibers before they are subjected to subsequent processing, i.e., dyeing.
Referring to FIG. 1, the conventional scouring for artificial fibers includes three successive steps. The artificial fibers with oils agents are scoured with strong bases and scouring agents, neutralized with weak acids, and finally, rinsed by hot water. The major drawback of such method is that it necessitates a large quantity of rinsing agents including water, scouring agents, strong bases, and weak acids, thus making the practice of this method costly. Moreover, a substantial quantity of wastewater will be produced from the rising agents, whose treatment also raises the costs. Another drawback of the conventional scouring is its low efficiency. In general, it takes about 45 minutes to complete the scouring process.